Skip the auto shop - Our mechanics make house calls

Q: After fuel pump replacement, no power getting to fuel pump - 1991 Toyota Supra Automatic

asked by on

My car was running on starter fluid and needed a fuel pump. I replaced the pump and cleaned the gas tank. Next, I tried to start the car and there was absolutely no power to the fuel pump. To make sure that the new fuel pump was working, I hooked it up to the tail lights and it worked. It pumps fuel to the engine, but I’m not getting any spark. A mechanic told me that most of the engine is not getting power. Except for the ignition and the alternator, everything else is not getting power. He also told me that the security light was on. I’m using a spare key that I had made to lock and unlock the doors. A friend told me that using that key in that way might have activated the security system and shut off power down to the engine. What is your diagnosis and how can I fix it?

A: I would start with clearing the security is...

I would start with clearing the security issue, because utilizing the wrong key (or a bad door sensor) can disable the fuel injection and fuel pump once the security system arms, as your mechanic notes. Once the security system is verified to be working properly, and out of the picture, make sure fuel injection, ignition and fuel pump fuses/relays are working properly, routing power to the ignition, injection computer and fuel pump. A YourMechanic professional can help diagnose this issue and get you on your way!

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Why the MegasquirtPNP Pro ECU blew all six ignition coils at first start

Hello. From what you describe it would appear to me that the aftermarket ECU may have been the cause of the issue. I would verify that the aftermarket ECU was properly installed, as that is the only common denominator that...

Q: Stalls idling cold start - 1983 Mercedes-Benz 380SL

Hello. Before replacing the fuel injectors my recommendation would be to have a fuel injector cleaning done. The injectors may still need to be replaced to solve your problem, but this is a good place to start. The idle...

Q: Fuel pressure low

Hi! I would recommend having a technician double check the fuel pump, filter, fuel lines, fuel related wiring, and fuses. It's always best to double check components pertaining to an initial concern in case something was missed. Also, there is...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...